BACKGROUND Profiling of the plasma indoles tryptophan, 5-hydroxytryptophan (5-HTP), serotonin, and 5-hydroxyindoleacetic acid (5-HIAA) is useful in the diagnosis and follow-up of patients with carcinoid tumors. We describe an automated method for the profiling of these indoles in protein-containing matrices as well as the plasma indole concentrations in healthy controls and patients with carcin...

The glycine site-specific N-methyl-D-aspartate (NMDA) antagonist 5-nitro-6,7-dichloro-2,3-quinoxalinedione (ACEA 1021, 4x30 mg/kg, i.p.) given 30 min before dexfenfluramine (4x15 mg/kg, i.p., every 2 h) was unable to prevent dexfenfluramine-induced depletion of 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA) content, and 5-HT transporter (5-HTT) density. Another glycine site-spe...

Carbon nanotube (CNT)-based microelectrodes have been investigated as alternatives to carbon-fiber microelectrodes for the detection of neurotransmitters because they are sensitive, exhibit fast electron transfer kinetics, and are more resistant to surface fouling. Wet spinning CNTs into fibers using a coagulating polymer produces a thin, uniform fiber that can be fabricated into an electrode. ...

Brain functions can be affected by the availability of dietary precursors of neurotransmitters. The diet induced increase in tryptophan (TRP) availability has been shown to increase brain serotonin (5-HT, 5-hydroxytryptamine) synthesis and various related behaviors. A prominent role of serotonin in memory functions is widely acknowledged. Increased brain 5-HT concentration is shown to enhance c...

Background Inflammatory processes are associated with depletion of the essential amino acid tryptophan, the precursor of serotonin (5-HT). We evaluated the peripheral responses of tryptophan and both peripheral and brain metabolism of 5-HT to intravenous lipopolysaccharide (LPS) administration in pigs. Methods In 6 crossbread barrows Escherichia Coli LPS was infused. Six pigs served as controls...

In a variety of vertebrates, highly aggressive individuals tend to have high social status and low serotonergic function. In the sex changing fish Lythrypnus dalli, serotonin (5-HT) may be involved as a mediator between the social environment and the reproductive system because social status is a critical cue in regulating sex change. Subordination inhibits sex change in L. dalli, and it is ass...

Anorexia or loss of appetite, one of the most typical symptoms observed in experimental and human cirrhosis, has been proposed to be associated with altered brain serotonin (5-HT) metabolism. In order to evaluate this hypothesis, brain 5-HT, its precursor tryptophan (TRP) and its metabolite 5-hydroxyindole-acetic acid (5-HIAA) were measured in brains of rats with thioacetamide (TAA)-induced liv...

This study investigated the relationship between platelet (PLT) serotonin (5-HT) and intestinal permeability in children with pervasive developmental disorders (PDD). Differential sugar absorption and PLT 5-HT were determined in 23 children with PDD. PLT 5-HT (2.0-7.1 nmol/10(9) PLT) was elevated in 4/23 patients. None exhibited elevated intestinal permeability (lactulose/mannitol ratio: 0.008-...